Originally Posted by
Checkboard
- China Airlines Airbus Industrie A300B4-622R, Nagoya Airport April 26, 1994
- Bournemouth Airport, U.K. - A Thomsonfly (now known as Thomson Airways) Boeing 737-300 with 132 passengers on a flight from Faro in Portugal to Bournemouth in England, September 2007
- An Air New Zealand Airbus A320-200, registration D-AXLA (ZK-OJL), test flight GXL888T from Perpignan (France), Nov 2008
- Turkish Airlines Boeing 737-800 at Amsterdam's Schiphol Airport, February 2009
etc etc All aircraft which crashed (or very nearly so) because the pilots failed to realise that the trim had been set full nose up, and couldn't understand why they lost pitch control.
Generally airline stall recovery training doesn't use or show a set up with the trim set this way - it is usually an artificial "
OK, we are going to stall ... disengage the autopilot and slow the aircraft down, and stop trimming to allow for the recovery..."
Agreed, it's a nasty pattern developing, and nothing to do with A vs B or FBW (everything to do with higher-level automation though).
However, it isn't at all clear that 447 fits this pattern. The trim up in this case is after the a/p drops out, and in response to pilot inputs. Initially at least, auto-trim is still active, and responding to nose up (to the stops) stick input.
It remains unknown from what info the BEA choses to give us at this point whether or not other control law transitions took place which might have kicked auto-trim out later. I think if direct law had engaged it would be clear and would have been reported - but I am not so sure about abnormal attitude law, looks like at some points at least they should have been in it, but BEA does not mention, possibly still trying to determine that.
One thing that does look clear, is that regardless of what the THS did, when they put the stick forward, it sounds like the a/c responded - reducing the pitch. It would appear the inputs were never held long enough to actually put the nose down.
Or in other words,
from what info we have, it doesn't
look like they lost pitch authority.